vehicle height is dependent on; 1. the height of the headlights (what he was probably measuring) and; 2. the lowest part of the vehicle can not be below the bottom of the rim.
there are other stipulations on vehicle height based on the vehicle's weight, but that is mainly an issue for commercial vehicles.

bottom line is that you're going to get attention in a car that calls for attention. keep it polite and to a minimum like you did and you won't get hassled too bad.